Publishers version - DTU Orbit

Figure 158: The ZephIR models which are used in the study. (Left) The commercial model
which is 1.7 m tall and 0.5 m width. The instrument weights 100 kg. (Right) The prototype
which is 1.5 m tall with adjustable legs. Including the signal processing unit, laser
source/sensor and battery which are separated from the head by means of an optical cable,
it weights 120 kg.
The staring mode approach was applied for the first time by Harris et al. (2006) with the
aim of investigating possibilities for controlling the wind turbine based on upstream wind
measurements with the prototype model of the ZephIR lidar. Subsequently, the prototype is
used in other experiments in this context, like by mounting on a wind turbine to measure
the wake behind (Bingöl et al., 2010; Trujillo et al., 2011), for synchronized multi-lidar field
measurements (Mikkelsen et al., 2008) and horizontal wind profile measurements (Bingöl
et al., 2009a).
12.2.2 Windcube
The second wind energy lidar that came into the market is the Windcube, developed by
the French company LeoSphere. Evaluation reports, mostly for the measurements over flat
terrain, are also available recently (Albers and Janssen, 2008).
Contrary to the ZephIR, Windcube is a pulse lidar, which measures the wind speed and
direction at measurement points 90 ◦ apart from each other on the conical scan circle for all
chosen heights simultaneously. Each sector is scanned for 1 s and every 6 s (2 extra seconds
are used to move the wedge), the values are used to derive wind speed and direction profiles;
calculated via (Lindelöw, 2007);
u =
u 2 1 +u2 2
where u1 and u2 are the horizontal plane wind speed components, derived as
and
u1 = vr(0)−vr(π), u2 = vr( π
2
w = vr(0)+vr(π)
2cosφ
= vr( π
3π
2 )+vr( 2 )
2cosφ
(266)
3π )−vr( 2 ) (267)
, Θ = arctan(u1,u2) (268)
DTU Wind Energy-E-Report-0029(EN) 233